class_docstr: Callable object storing the details of one alias.
  
  Instances are registered as magic functions to allow use of aliases.
code: def __call__(self, rest=""):
      cmd = self.cmd
      nargs = self.nargs
      # Expand the %l special to be the user's input line
      if cmd.find("%l") >= 0:
          cmd = cmd.replace("%l", rest)
          rest = ""
  
      if nargs == 0:
          if cmd.find("%%s") >= 1:
              cmd = cmd.replace("%%s", "%s")
          # Simple, argument-less aliases
          cmd = "%s %s" % (cmd, rest)
      else:
          # Handle aliases with positional arguments
          args = rest.split(None, nargs)
          if len(args) < nargs:
              raise UsageError(
                  "Alias <%s> requires %s arguments, %s given."
                  % (self.name, nargs, len(args))
              )
          cmd = "%s %s" % (
              cmd % tuple(args[:nargs]),
              " ".join(args[nargs:]),
          )
  
      self.shell.system(cmd)
  
imports: import os
  import re
  import sys
  from traitlets.config.configurable import Configurable
  from .error import UsageError
  from traitlets import List, Instance
  from logging import error
label_desc: Use image node_id 4 for calling the Alias obj's underlying member method code with example usage: obj.__call__(rest) without return types